[cma]

> I can't speak to why they have been stuck there for so long.

Semiconductor manufacturer has been able to use refractive optics (lenses) for decades and decades. The biggest change until now was to immersion lithography as we started getting into UV. Now we're into EUV (extreme UV). Lenses no longer work, everything has to be done with reflective optics (and even then the mirrors get ablated over time). It's the biggest single change in lithography we've seen and Intel still hasn't been able to pull it off in volume.